GE CTR 80 manual Setup, RS-232 Cable Wiring for, IBM PC and Compatibles, Baud Rate

10 Digital Communication Interface

10.1.1Wiring

The serial communications ca- ble attaches to the calibrator through the DB-9 connector at the back of the instrument. Fig- ure 5 shows the pin-out of this connector and suggested cable wiring. To eliminate noise the serial cable should be shielded with low resistance between the connector (DB-9) and the shield. If the unit is used in a heavy industrial setting, the se- rial cable must be limited to ONE METER in length.

10.1.2Setup

Before operation the serial in- terface must first be set up by programming the baud rate and other configuration parameters. These parameters are pro- grammed within the serial inter- face menu. The serial interface parameters menu is outlined in Figure 4 on page 36.

	RS-232 Cable Wiring for
	IBM PC and Compatibles
Instrument	Computer (DTE)
Connector	Connector
(DB 9-Pin)	(DB 9-Pin)
1 NC	1 DCD
2 RxD	2 RxD
3 TxD	3 TxD
4 NC	4 DTR
5 GND	5 GND
6 NC	6 DSR
7 RTS	7 RTS
8 CTS	8 CTS
9 NC	9 NC
Instrument	Computer (DTE)
Connector	Connector
(DB 9-Pin)	(DB 25-Pin)
1 NC
2 RxD	2 TxD
3 TxD	3 RxD
4 NC	4 RTS
5 GND	5 CTS
6 NC	6 DSR
7 RTS	7 GND
8 CTS	8 DCD
9 NC	20 DTR

Figure 5 Serial Cable Wiring

To enter the serial parameter

programming mode first press “EXIT” while pressing “SET” and release to en- ter the secondary menu. Press “SET” repeatedly until the display reads “PAr”. Press “UP” until the serial interface menu is indicated with“SErIAL”. Finally press “SET” to enter the serial parameter menu. In the serial interface parame- ters menu are the baud rate, the sample rate, the duplex mode, and the linefeed parameter.

10.1.2.1Baud Rate

The baud rate is the first parameter in the menu. The display prompts with the baud rate parameter by showing “bAUd”. Press “SET” to choose to set the baud rate. The current baud rate value is displayed. The baud rate of the instru- ment serial communications may be programmed to 300, 600, 1200, 2400, 4800, or 9600 baud. The baud rate is pre-programmed to 2400 baud. Use “UP” or “DOWN” to change the baud rate value. Press “SET” to set the baud rate to the new value or “EXIT” to abort the operation and skip to the next parameter in the menu.

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